Drill retainer



J. ,C. CURTIS DRILL RETAINER July 24, 1934.

Filed-.April 25. 1932 JaH/v 6. 606 5 INVENTOR ATTORNEY Patented July 24, 1934 DRILL RETAINER.

John 0. Curtis, Cleveland, Ohio, assignor to The Cleveland Rock Drill Company, Ohio, a, corporation of Ohio Application April 25,

7 Claims.

The present invention relates broadly to rock drills of the percussion type but is more particularly concerned with improvements in steel or tool retainers therefor.

One of the objects of this invention is to provide a releasable tool retainer whic is simple in design, economic of manufacture, and one which is susceptible of ready operation.

Another object is to provide a tool retainer which is so constructed as to prevent the acci dental disengagement of the tool or steel from the drill.

Other objects and advantages of the present invention will appear as the description proceeds.

In the accompanying drawing wherein like reference characters indi ate like parts throughout the several views:

Fig. 1 is an elevational View partly in section of the lower or front end portion of a rock drill illustrating the tool retainer of this invention attached thereto.

Fig. 2 is a similar view taken at right angles to Fig. 1.

Fig. 3 is an end elevational view of Fig. 1.

Fig. l is a view similar to Fig. 3, illustrating the retainer shifted to inoperative position.

Referring now in detail to the drawing, represents the front housing of a rock drill, which is provided with a bore 11, and enlarged counterbcre 12. Slidaoly mounted within the bore 11, there is the 13 of a cutting tool 14. The penetration of the shank within the front housing is limited by the engagement of an integral collar 15 with the face or shoulder 16, formed at the intersection of the bore 11 and counterbore 12.

Qpening into the counterbcre 12 and disposed in parallel alignment with the counterbore 12, there is provided an opening or slot 17, being terminated, toward the face 16, by an enlarged circular recess 18. Diainetrically opposed to the slot 17, there is provided a similar slot 19 being connected to the exterior by an opening 20, disposed at right angle from the slot 19. Adjacent the slot 19 and opening 20, the housing 10 is provided with an integral supporting lug 22 provided with a transversally disposed recess 23.

The retainer comprises a yoke 24 formed with a substantially semi-circular loop 25. Extending from the ends of the loop 25, there is two integral arms 26 and 27. The arm 26 is capable of rotatable engagement within the slot 17 and is terminated by a head 28 rotatably disposed within the recess 18, and engageable with the bottom thereof to prevent the longitudinal removal-of the yoke from the front housing 10.

Cleveland,

1932 Serial No. 607,244

The arm 27 is conveniently machined to permit its introduction within the slot 19 through the opening 20. The outer end portion of this 'arm is bent at right angle to aiiord a tongue 29 capaole of engagement within the recess 23.

Opening into the recess 18, there is provided Within the wall of the front housing 10, a square bore 30, within which is slidably disposed a square plunger'3l. This plunger by virtue of its square cross section within a corresponding bore is held I against rotation and has its end, adjacent the opening of the bore 30, provided with a transversally disposed lug 0r rib 32. The head 28 of the retainer arm 26 is provided with two transversally disposed grooves 33, within which the rib 32 is capable of engagement and may be maintained therein by the pressure exerted by a compression spring 34 which is disposed Within the bore 30, rearwardly of the plunger 31. The square plunger 31 is located within the corresponding bore in such a manner as to afiord the engagement of the rib 32 within one of the grooves 33 when the yoke 24 is positioned as illustrated in Fig. 3 and Fig. 4. The frictional engagement of the rib 32 with the side wall of the grooves 33, affords an eficient locking device for the yoke, preventing thereby its accidental shifting from the operative position to the inoperative position.

Diametrically opposed to the square bore 30, there is provided, Within the Wall of the front housing 10, a bore 35 terminated by a restricted screw threaded portion 36. Slidably disposed within the bore 35, there is a plunger 37 which is attached in any suitable manner, as for instance by means of cement, to a resilient member 38, preferably made of rubber. This member and consequently the plunger 37 are secured within the bore 35 by a screw 39 in engagement within the restricted screw threaded portion 36. That screw may be secured to the member 38 in any suitable manner, it may for instance be vulcanized therein. The plunger 35 protrudes a convenient amount from the bore 35 and has its protruding end beveled to permit the passage of the tongue 29.

When the retainer is shifted into an operative position, the tongue 29 being in engagement upon the lug 22 will pass under the plunged 3'7 by compressing the resilient member 38. Subsequently the tongue 29 will fall into the groove 23 and will be maintained therein by the pressure exerted by the plunger 37, thus cooperating with the locking device provided upon the head 28 to prevent the accidental shifting of the yoke from an operative into an inoperative sition. When the yoke 24 is in the operative position, the drill is prevented from sliding outwardly from the front head 10 by the engage-- ment of the loop 25 with the collar 15. When it is desired to remove the tool fr :1 the drill, the retainer or yokeZd may, be ionedgas i1- lustrated-in Fig-J4, byforcing the. tongue-.29 out of engagement from the recess 23, therib 32 out of engagement from one of the grooves 33. The retainer will be locked into the opened? position by the frictional engagement'of the rib, 32 within the other of the grooves 33. In this last mentioned position of the yoke the plunger 7 35 is retained within the bore. 35=by its. ass tion with the member 38 as previously explaii During the drilling opera tion,,it is .of;ten. .nec.- essary for the operator to continue such operation until the lower face of the yoke becomes. in contact with the surface of the material being drilled, thus imparting 'an-upwardpressure upon the yoke and tending to cause the disengagement of the tongue29 from-the recess 23 and allow the accidental shifting of the retainer into an' inoperative position. This detrimen feature is overcome by the engagement of rib 32 within one of the grooves 33. Any forces acting in an upward directionwill have the tendency to further compress the spring .4 and consequently increase the pressure of plunger 31 or increase the frictionalengagement of the rib 32 within the corresp'onding groove thus preventing accidental shifting of the retainer into an inoperative position.

Although the foregoing description is. neces sarily of a detailed'character, in order to completely set forth the invention, it is tov be understood that the specificterminology is not in tended to be restrictive or confining and it is to be further understood that variousrear-ranga ments of .parts andmodification of. structural detailmay be. resorted .to without departing. from the. scope .or spirit of. the invention. as herein claimed.

I claim;

1. In ..a drill.retainer,.afront headxhaving a borev for. receiving the drill, a groovedlug intee gralwith said front head, a yoke having arms integral therewith, one of said arms ,being terminated by. a head. rotatably mounted within a recess provided within said front head, said head pivotally. securingwsaidnyoke to said fronthead, the. other .of. said arms being bent to form a tongue engageablewithin theigroove of said lug to.lock saidyokeinioperative positiornand means resiliently engageablewith said tongue to effect pressurehthereon for maintainingsaid tongue within said groove.

2..In. a drill retainer, a front head having a bore to receive the drill, a yoke-having integraltherewith and being-pivotally securedto said "front head by-one of said arms, and opening. within. .said .front head. throughv which the other vof saidarms may pass topc sition said yoke into operative Qrinoperativ'e relation with re.- spect to said drill, and locking means capable of engagement with each of said arms to hold said yoke in operative position. I

3. In a drill retainer, a front head having a bore to receive the drill, a yoke having arms integral therewith and being pivotally secured to said front head by one of said arms, an opening within sjaid front headithroughwhich-the other 1 of I said armszis free to pass for locating yoke into operative or inoperative position, locking means capable of engagement with each of said arms to hold said yoke in operative position and withone of said arms to hold said yoke in inoperative position.

i; In a drill retainer, a front head having a bore for receivingthe drill, a grooved lug integral with said front head, a yoke having arms extendingupwardly therefrom, said yoke being pivotally secured to said front head by the extrernity of one of said arms, the other of said arms being formed with a tongue engageable with the-groove of saidlug to lock said-yoke in operative position, and means resiliently en.- gageable with said tongue toeffect pressurethereon for maintaining saidv tongue within said groove.

5. In a drill steel retainer, a=housi-ng having a bore for receiving-the shank of a colla-red drill steel, a counterbor'exwithin which the-collar of said drillsteel is free to-slide, a yoke-having arms extending upwardly therefrom, means for pivotallysecur-ing said yoke to said housing by one of said arms, said yoke being normally located adjacent the front end of said housingrfor engagement with. the collar of said drill steeL-and further means permitting-the. passage of the other ofsaid armsaway from said housing when said yoke is shifted from operative into inoperative position. I

6. Ina drillisteel retainer, a housing having a bore for receivingthe shank of a drill steel, a collar on said drill steel, 21 counter-bore Within said. housing within which-said collar is free to slide, a yoke moving a duality of arms-integral therewith,-said arms being-substantially ens. tirely within saidhousing when said yoke is positioned for operative. engagementwith said 001- lar, means for pivotally. securing said yoke to said housing by oneofsaid arms,- and further meanspermitting the passage of the other. of said arms awayfrom said housing whensaid yoke is ,shifted from operative into inoperative position. 7

7. In a drill steel retainer, a housing having a bore for receivingthe drill, a yoke having arms extending upwardly therefrom, saidyo-ke being suspended into operative engagement said drill to said housingbymne-of: said arms pivg otally secured in the" interior; of said housing, the other of said arms being capabletofenfgagement withsaid housing for cooperatin thesuspension of said yoke, and a passage w in; said housing through which said last tioned arm is free to' pass whensaid yok shifted from operating'into inoperating posit on, H

' JoHI- o. CURTIS. 

